Spermatogenesis is initiated in the male testis with the beginning of puberty. This comprises the entire development of the spermatogonia (former primordial germ cells) up to sperm cells. The gonadal cords that are solid up till then in the juvenile testis develop a lumen with the start of puberty. They then gradually transform themselves into spermatic canals They are termed convoluted seminiferous tubules (Tubuli seminiferi contorti) . They are coated by a germinal epithelium that exhibits two differing cell populations: some are sustentacular cells (= Sertoli’s cells) and the great majority are the germ cells in various stages of division and differentiation.

development of the germ cells begins with the spermatogonia at the periphery of the seminiferous tubule and advances towards the lumen over spermatocytes I (primary spermatocytes), spermatocytes II (secondary spermatocytes), spermatids and finally to mature sperm cells.

The Sertoli cell is essential for spermatogenesis as it provides support for the developing sperm cells – moving them towards the lumen of the semiferous tubule as they develop until maturity when they are released. The Sertoli cell also reduces motility and capacitation (initiation of the acrosome reaction) of the sperm cells so viability is maintained.

Spermatozoa are produced in seminiferous tubules in the testes. They start off as spermatogonia , undergoing mitosis becoming a type A spermatogonium or a type B spermatogonium.

Type B spermatogonia become primary spermatocytes.

Primary spermatocytes go through a meiotic division to become secondary spermatocytes, which undergo another meiotic division to become spermatids.

Type A spermatogonia stay as spermatogonia, and do not change. They act as stem cells and will divide again producing more Type A and B cells.

Each primary spermatocyte divides into two secondary spermatocytes containing two sets of chromosomes (2 × 1N).

The secondary spermatocytes then divide into two spermatids, each containing just one set of chromosomes (1N), half the DNA needed to make a human being. (The other half will come from the ovum at fertilisation)

The barrier is formed by layers of cells from the VASCULAR ENDOTHELIUM of the capillary BLOOD VESSELS, to the SEMINIFEROUS EPITHELIUM of the seminiferous tubules. TIGHT JUNCTIONS form between adjacent SERTOLI CELLS, as well as between the ENDOTHELIAL CELLS.

*Slide easy to identify as you can also see many other structures with it, and also do not confuse with ureter or urethra, this does not have urothelium, and the urethra’s lumen is long, and thin and irregular. This lumen is wide, kinda circular, and irregular.

Development of Testis, Epididymis, Ductus Deferens
Until week 6, the embryo does not show a particular gender at all
At week 7 till week 20, embryo under a series of changes until a male or female phenotype is recognized

Gonads become ovaries or, in the case of the male, the testis
The primary genital duct that develops in the male is Mesonephric duct (Think M= male)

In order for males to become males, they have a specific gene = TDF, or testis determining factor

Seminiferous cords have the primordial germ cells and Sertoli cells – that secret MIF (Mullerian inhibiting factor), that supresses the development of the primary genital duct in female = the paramesonephric duct or mullerian duct.

NEWS!!!!

Print Version of all 40 topics are at Life Science Building Copy Shop!! Get yours today!

NEW!!! Link to PDF versions of Topics !!!! See Topics or About Page.

About This Site:

This site was made for the Anatomy, Histology, Embryology class in 2nd yr, 1st semester at the University of Debrecen. All theoretical topics are listed as described on the website of the Anatomy department.

We combined Practical class notes, Moore, Board Review Series textbooks of Gross Anatomy and Embryology, Langman’s, DiFiore’s, as well as the Lab manual for Histology at Semmelweiss. We believe it to be all inclusive of the material you will need for your test. We made them for ourselves, but since people asked for them, and emailing them seemed next to impossible, we decided to post them here.

On the left are the newest topics we’ve added.

To see all the topics we’ve done so far, scroll down and click on the Category you would like to see:
Head & Neck, Thorax, Abdomen, & Pelvis.

Added a search box in the sidebar, so you can search for the item you want.

But the best way to find the topic that you want?

Scroll down and click on the “Link to Topics” Page. There is the list of all topics. If a link to your topic of choice exists, we’ve started/finished it, else we’re working on it. There! That’s easier, isn’t it?

We’ve added pictures, links, and animations where we have found them.

Hope this helps you, and GOOD LUCK!

(P.s. If you find mistakes, or want to add info, or find something we missed, please comment below the post in question, and we will fix or add it. )